In several industrial sectors, machines are used for positioning initially randomly arranged articles into a predetermined position and/or into an aligned arrangement. More specifically, in the packaging field, machines are used to put empty bottles or containers upright and align them. A type of positioning machine is known that is suitable for putting in the upright position containers of the type defining a longitudinal body with a base at one of its ends and an opening for filling the container on the other end, such that they rest on their base and with said opening for filling the container in an upper part thereof. The opening for filling the container generally forms a neck constituting a geometric shape that is different at the end opposite to the base.
Patent document U.S. Pat. No. 3,295,659 describes a machine based on an operating principle which has become the most widely used in many types of article positioning machines. Such principle is based on the handling of the mentioned different geometric shape to put the articles upright and comprises first individually arranging the articles in a housing in a horizontal position and with the longitudinal axis of the article pre-oriented according to the direction of said housing, such that the different geometric shape is facing either end of the housing, and then allowing the article to fall due to gravity through an open bottom of the housing into an alignment conduit. There are abutment and support configurations in the house intended for supporting said different geometric shape whatever its relative position is with respect to the housing so that the article always drops on its base into the alignment conduit. The machine adopts a rotary configuration in which a plurality of said cavities intended for receiving an article are radially arranged on the periphery of a circular structure.
Other more recent rotary positioning machines are known which are intended for empty lightweight bottles or containers, comprising a series of housings attached to a rotating structure, arranged tangentially on the periphery thereof, around a container receiving the articles in a random arrangement and means for leading in each housing a container or bottle in a horizontal position, with its longitudinal axis pre-oriented according to the tangential direction of the housing and with the neck either in the front part or in the rear part with respect to the rotation direction. Each of the mentioned housings has an open bottom over an alignment conduit which moves together with it and means are provided for allowing a container to drop upright from each housing into its corresponding alignment conduit through a drop site in the course of each turn. Deflector means for finally transferring the vertically oriented containers from the alignment conduits to an outfeed conveyor.
Given that a container in the horizontal position occupies a portion of the perimeter of the container that is greater than an upright container, it is possible to arrange along the length of the lower part of the perimeter of the container more compartments for upright containers than housings for horizontal containers in the upper part. This means that each housing can discharge upright containers in more than one compartment in the course of each turn.
Patent document U.S. Pat. No. 3,662,872 discloses a positioning machine with two drop sites per turn, in which each alignment conduit is vertically divided into two equal compartments by a wall and a divider plate is arranged in a hinged manner at an upper end of said wall and actuated by actuation means to alternately change position for the purpose of directing the articles which drop from the housing into either of said compartments in the course of each turn. The machine is therefore able to discharge from each peripheral housing, and through the two drop sites, two articles in each alignment conduit in the course of a turn.
Patent document EP-A-0945374 describes a rotating machine for orienting containers, particularly empty plastic bottles, provided with multiple drop sites per turn. This machine comprises a central hopper and a rotary structure on the periphery of which there are a plurality of housings. Each peripheral housing is associated with a corresponding alignment conduit located below it and which moves together with the conduit. Located under the alignment conduits there are a series of compartments provided with rollers for rolling over a peripheral track and linked to a drive chain which moves them in the same direction in which the structure rotates. Each drop conduit has as many corresponding lower compartments as drop sites in the circumference of the machine and the mentioned peripheral track on which the compartments move define a sinusoidal shape in relation to each drop site elongating the trajectory enough to misalign the position of a compartment with respect to the corresponding alignment conduit before passing through each drop site. A support plane is arranged between the drop conduits and the compartments having cutouts so as to allow the passage of the containers when a drop conduit is aligned with an empty compartment.
This system, however, is excessively complex given that each compartment must be constituted by way of a small carriage to be driven and led over a peripheral sinusoidal track provided with support rollers for rolling over a horizontal portion of the track for the purpose of counteracting the forces due to gravity, and other support rollers for rolling over a vertical portion of the track to counteract the forces due to traction of the drive chain, this vertical portion of the track being what defines the sinusoidal shapes. It must be taken into consideration that for example in a normal sized machine with 28 housings along its circumference and three drop sites, 84 rolling compartments linked to the drive chain would be necessary, which means a high manufacturing cost, excessive assembly complexity and low operating reliability.
One aspect of the present invention is to provide an apparatus and method for positioning articles, based on the known principle of articles falling from housings into alignment conduits, comprising multiple unloading operations per cycle, which is able to position multiple articles by means of each housing in the course of each cycle using a relatively simple, economical and reliable mechanism.